Chromium change: https://source.chromium.org/chromium/chromium/src/+/84207093245c10ab466e5e0e549e2f31e2d6c644 Deprecates MultiWindowUtils.getInstanceCount(). This CL migrates the final usages of getInstanceCount() to getInstanceCountWithFallback(). Bug: 430092908 Change-Id: Icd365bc340a00079d19ab08d250626ff48f1d05f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7141127